Clinical Manifestations of COVID-19 Breakthrough Infections: A Systematic Review and Meta-Analysis

Lee, Christine, Woo, Wongi, Kim, Ah Young, Yon, Dong Keon, Lee, Seung Won, Koyanagi, Ai, Kim, Min Seo, Tizaoui, Kalthoum, Dragioti, Elena, Radua, Joaquim, Lee, Sungsoo, Smith, Lee and Shin, Jae Il (2022) Clinical Manifestations of COVID-19 Breakthrough Infections: A Systematic Review and Meta-Analysis. Journal of Medical Virology. ISSN 1096-9071

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Abstract

Objective- To provide a comparative meta-analysis and systematic review of the risk and clinical outcomes of COVID-19 infection between fully vaccinated and unvaccinated groups. Methods- Eighteen studies of COVID-19 infections in fully vaccinated (“breakthrough infections”) and unvaccinated individuals were reviewed from Medline/PubMed, Scopus, Embase, and Web of Science databases. The meta-analysis examined the summary effects and between-study heterogeneity regarding differences in the risk of infection, hospitalization, treatments, and mortality between vaccinated and unvaccinated individuals. Results- The overall risk of infection was lower for the fully vaccinated compared to that of the unvaccinated (relative risk[RR] 0.20, 95% CI 0.19-0.21), especially for variants other than Delta (Delta: RR 0.29, 95% CI 0.13-0.65; other variants: RR 0.06, 95% CI 0.04-0.08). The risk of asymptomatic infection was not statistically significantly different between fully vaccinated and unvaccinated (RR 0.56, 95% CI 0.27-1.19). There were neither statistically significant differences in risk of hospitalization (RR 1.06, 95% CI 0.38-2.93), invasive mechanical ventilation (RR 1.65 ,95% CI 0.90-3.06), or mortality (RR 1.19, 95% CI 0.79-1.78). Conversely, the risk of supplemental oxygen during hospitalization was significantly higher for the unvaccinated (RR 1.40, 95% CI 1.08-1.82). Conclusions- Unvaccinated people were more vulnerable to COVID-19 infection than fully vaccinated for all variants. Once infected, there were no statistically significant differences in the risk of hospitalization, invasive mechanical ventilation, or mortality. Still, unvaccinated showed an increased need for oxygen supplementation. Further prospective analysis, including patients’ risk factors, COVID-19 variants, and the utilized treatment strategies, would be warranted.

Item Type:	Journal Article
Keywords:	COVID-19, Breakthrough infection, Clinical Manifestation, Review, Delta Variant, Vaccine Effectiveness
Faculty:	COVID-19 Research Collection Faculty of Science & Engineering
SWORD Depositor:	Symplectic User
Depositing User:	Symplectic User
Date Deposited:	19 May 2022 08:15
Last Modified:	19 May 2023 01:02
URI:	https://arro.anglia.ac.uk/id/eprint/707603

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